Hi rvw,
As you know there are many choices but I think highly of all of them. Each of them will help you choose the design that has the best chance of success for your body type, sleeping positions, and preferences. After that it’s a matter of which one is the best “match” for you based on your personal value equation. In terms of quality or value there would really be no “mistakes” with any of them.
Their toppers are Dunlop.
I’m not sure why that’s happening but you may be using the wrong search window or your search may be using the default for the “find post from” setting of “a year ago” instead of “any date”. There’s more about searching the site or the forum under the help tab here.
Center zoning can certainly be useful for those where the pelvis sinks down too far or they need firmer support under the lumbar but they also need soft sections under the shoulders to “allow” the shoulders to sink in enough. As with any other design or theory … it always depends on the specifics of a particular mattress and on how well a mattress matches your body type and sleeping positions in terms of PPP. There is more about zoning in this article and in post #11 here.
There are many versions of “dual springs” depending on the specifics and what they mean but once again the benefits will depend on how well the mattress as a whole matches your specific needs and preferences in terms of PPP. Your own testing results are always more important than any “theory” or “story” that may benefit someone else but not you.
You can read my thoughts about airbeds in this article. Of course like anything else that doesn’t mean that some people won’t do well with them … but overall I am not a “fan” of airbeds.
You can see my thoughts about a solid platform in post #10 here and the bed rug it links to can reduce the risk of a non breathable support surface if the other risk factors seem to indicate it’s necessary.
Questions are a “good” thing and always welcome for a purchase as important as a mattress
I’m looking forward to finding out what you end up choosing and of course any feedback you have the chance to share along the way.
Phoenix